The present disclosure relates to image processors represented by imaging devices such as digital cameras and video cameras (camcorders) for capturing consecutive images.
Many complementary metal oxide semiconductor (CMOS) imaging elements use a rolling shutter technique for allowing exposure to sequentially start for each horizontal line (hereinafter referred to as “line”), and sequentially reading image signals of respective lines to form a frame. In the imaging element using the rolling shutter technique, the starting time and ending time of the exposure period differ for each line. Therefore, if an external flash etc. is used during a period that is shorter than one frame period, a band of high luminance (a flash band) may appear on an output image of the imaging element.
International Patent Publication No. WO 2010/100866 discloses a technique for compensating for a flash band by adding image signals of two consecutive frames affected by flash.